2.009 Product Engineering Process is an iconic product design class in engineering department. Seniors, in teams of around 20 people, need to develop a project from scratch to working prototypes in 3 months. The course is all about process - We developed an add-on layer for fishermen that will double their survival time in freezing water and drastically increase their chances of getting rescued.
Commercial fishing is one of the most dangerous occupations in the United States. Fishermen can be on the water for up to ninety days, facing zero degree water, and fifty miles offshore.
In the case of emergencies, which can range from stormy waters to onboard fires, fishermen are mandated to have survival suits for every crew member. Survival suits are waterproof drysuits that keep fishermen afloat and protect them from the freezing water for six hours.
In the midst of a vessel disaster this is how the crew is trained to respond:
- The captain is alerted about the problem and yells for the crew to start their emergency procedures...
- A deckhand runs and grabs all the survival suits...
- Everyone puts on their suit and activated their floatation...
- They jump in the water knowing the suits give them six hours.
Every single emergency procedure could have been flawlessly executed, but the fishermen still know they only have six hours. After learning about this problem and interviewing fishermen, we decided to create VESTA. It will double the time fishermen have in water drastically increasing their chances of getting rescued by the coast guard.
To test how VESTA could help maintain the body temperature under extreme circumstances, we did two six-hour tests in an inflatable pool in a parking lot at MIT. Brandon got into 2-degree water with/without VESTA inside his survival suit. While not wearing VESTA, his temperature drops quickly and we had to pull him out because we could not risk him getting hypothermia.
Brandon then put on VESTA, which fits under the survival suit and went in on a different day. VESTA drove his temperature to 34 degrees Celsius and kept it there. There was no statistically significant change in temperature over the entire six hours. VESTA’s six hours of power coupled with his survival suit would extend his survival time to twelve hours.
When we designed VESTA, we had three main goals:
- Six-hour warmth support
- Absolutely safe
- Easy to put on
To achieve these goals, we:
- Use 33 lithium magnesium oxide battery cells, weighing about 8 pounds (slightly less than a gallon of milk), to supply totally 200 watts of power to keep people alive in freezing water. This is the same power output as an electric blanket. Over 6 hours, we need a total of 4.3 mega-joules of energy, the same as a car battery.
- Send energy stored in the batteries to 4 heating pads, made out of waterproof, flexible silicone. We placed the heating pads over the heart and major organs to maintain the core temperature and to circulate heat throughout the body. A thermal sensor measures the surface temperature of the heating pad. The temperature is automatically regulated to keep the body at a safe temperature. When the heating pads reach 53C, they turn off. When they drop to 45, they turn back on.
Our main challenge with having batteries and electronics in water is safety. We have dual-safety protections. From batteries to wiring connections, every electronic enclosure in VESTA is tested to be waterproofed, and everything is enclosed in our waterproof vest.
To make the vest waterproof, we are using a special nylon as the outermost skin. This fabric is used in other floatation devices and resistant to ripping. Next, we have an insulation layer that helps retain heat and prevent the fishermen from feeling too warm.
- We’ve designed VESTA to be easy to use. Fishermen would simply put VESTA over their head and use velcro straps to fit around their body. In order to activate the heating pads, fishermen just need to push the power button. Survival suits are designed to be one size fits all, and so is VESTA.